Making fleece liners- not skilled in sewing

Anyone know if there is a certain way that these liners need to be sewed, as far as safety to the chin? I think I could figure out how to set up the sewing machine for basic stitching, would I need to do a few layers of stitches to keep it strong and safe?



Also if anyone has a pattern?... It would be awesome too! I believe it's going to be a critter nation(the person I'm buying from has both cn and fn cages so I'm just trying to remember which I'm purchasing)



Thanks for any help!